US 8236220 B2
An embedded-object composite product including a solid-state mass of PET, an object embedded in the PET material mass, and a zone possessing a continuous material-density gradient in the PET material mass, with more-dense PET material residing closely adjacent the embedded object, and less-dense PET material residing more distant from that object. This product is produced effectively by non-destructively heating the PET mass from its solid state to allow it to flow as a liquid, by then pressing the object into the heated PET mass to perform object embedment and to create a declining PET-material density in the region adjacent, and progressing from adjacent, the embedded object, and by thereafter cooling the mass to re-solidify it.
1. A method of forming an embedded-object, composite-material product utilizing a solid-state mass of PET as an embedding-and-object-receiving (EOR) material, said method comprising
establishing, in a prospective contact-interface region intended ultimately to exist between an embedded object and a selected, solid-state mass of EOR material, a level of heat which, when exposed to that selected mass, is sufficient to cause EOR material therein to undergo a non-destructive, reversible state change from solid to flowable-liquid,
positioning an object which is to be embedded in the EOR mass, and the mass per se, in relative juxtaposition adjacent the intended contact-interface region,
with said positioning accomplished, and using relative-motion pressure adjacent the intended contact-interface region, advancing the to-be-embedded object into an embedded and received condition in the EOR material mass utilizing liquid flow in the EOR mass to accommodate such embedment,
by said advancing, realizing the once-intended contact-interface region between the now-embedded object and the EOR mass,
following said realizing, cooling the realized contact-interface region to return the EOR material therein to a solid state, and
by said cooling, creating the intended, embedded-object composite product.
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7. A method of uniting embedding and embeddable components comprising
providing, in a solid-state condition, and as an embedding component, a predetermined-volume mass of an embedding material which is non-destructively heatable and coolable to switch reversibly between solid and liquid states,
heating, in relation to a selected embeddable component, at least an appropriately sized portion of the provided mass to liquefy that portion,
pressing at least a portion of the selected embeddable component completely into the liquefied mass portion thereby to produce a condition of embedment wherein the overall embedding-component material and the embedded portion of the embeddable component collectively possess a volume substantially equaling the mentioned predetermined-volume, and
thereafter, cooling the liquefied embedding-material mass portion to solidify it.
8. A method of forming, without material removal, a composite-material, embedded-component product comprising
preparing an embedment-receiving region in a body for an embeddable component of a receiving component without removing material from that body. including heating, in relation to a selected embeddable component, at least an appropriately sized portion of the provided body to liquefy that region, and
also without performing any material-removal action, but in a manner reducing the volume of the receiving component, pressing an embedment component at least partially into the prepared embedment-receiving region to produce the desired embedded-component product, wherein, within and throughout the embedment-receiving region, an overall, intimate contact interface exists between the receiving and embedded components.
This application claims filing-date priority to U.S. Provisional Patent Application Ser. No. 60/838,457, filed Aug. 16, 2006, for “Embedment Manufacturing Procedure and Structures Produced Thereby”. The entire disclosure content of that provisional application is hereby incorporated herein by reference.
This invention relates to a unique manufacturing technique involving the manufacturing embedment of one or more different kinds of component(s) into a heat, and applied-pressure, state-change receiving material, and to various types of resultant composite-material products produced thereby. The invention is particularly illustrated and described herein in relation to such a manufacturing technique which results in the creation of a variety of special-purpose panel structures which may be designed and configured to perform unique functions, and to possess unique composite characteristics that are useful, in many different end-use applications. While such panel structures serve well to illustrate the advantages and versatility of the invention, and accordingly have been chosen herein as appropriate invention-disclosure “vehicles”, but it should be clearly understood that non-panel, composite-material products are just as readily and advantageously produced in accordance with the practice and features of the invention.
Fundamentally the invention involves, in terms of a preferred manufacturing technique, the use of appropriate heat and a slight amount of simultaneously applied pressure, in the context of relative-motion pressure-“driving” a chosen, embeddable object into a mass of specially selected, temporarily flowable receiving material—a receiving material which readily accommodates a selectively reversible, non-destructive phase, or state, change from solid to liquid-flowability, thus to permit a resultant embedding of the chosen object in the material. With this fabrication approach, different kinds of useful objects, such as fabric living hinges, fastening devices, wiring, fluid-conduit structures, acoustic sensors, radioactivity sensors, thermal sensors, radio antennae, and many others may be incorporated securely in surrounding, dimensionally and configurationally stabilized support material for otherwise normal functioning therein. For example, a specialized vehicle door panel, shaped appropriately for a particular vehicle and use application, might, in accordance with the practice of the invention, be embedment-formed with an embedding-material main body carrying embedded fabric living hinges, embedded radio-transmission antenna wiring, electrical heating wiring, outwardly accessible fasteners adapted to accommodate the attachment of various external hardware, and so on.
An especially interesting feature is that small embedded objects, such as fasteners, having shapes which, on balance, lack, in an overall sense, axes and overall outer surfaces of revolution, such as hex-head and square-head nuts, may be embedded easily to become fully stabilized against loosening rotation within the selected embedding receiving material. Another interesting feature is that all aspects of embedment as practiced in accordance with the invention involve no material removal (and hence material waste) steps. A further feature to note is that embedment “binding” of an embedded object in place in the embedding receiving material occurs without the need for any auxiliary adhesives.
From the several specific illustrations given here, and hereinbelow, those skilled in the art will quickly appreciate the special utility of the present invention.
The selected, special material in which embedment takes place, also referred to as an embedding-and-object-receiving (EOR) material, preferably takes the form of a closed-cell, thermoformable foam material designated by the initials PET, which initials stand for the material known as polyethylene terephthalate. While different, specific thermoformable PET materials may well be chosen for use in the practice of this invention, we have found currently that a particularly preferred material is a polyethylene terephthalate, closed-cell, 6-24# foam product made by Sealed Air Corporation in Saddlebrook, N.J. An excellent body of technical information relating to this PET material, herein referred to also simply as PET, is available from the well known Internet source of wide-subject-matter general information known as Wikipedia, The Free Encyclopedia.
We have discovered that this PET material, through the appropriate introduction thereinto of appropriate heat of above about 300-degrees F., changes from a solid state to a “precursor” flowable state, without vaporization or flaming. This state change to initial material flowability then affords the opportunity, utilizing a very slight amount of relative-motion pressure, such as about 5-10-psi, easily to embed, into a portion of a mass of such heated PET, fully or partially, different kinds of objects, such as those just suggested above.
In accordance with practice of the invention, pressing of an object into the thus-heated, “now-flowable” PET mass region, causes PET material to yield appropriately, and entirely “locally”, to the “incoming” object, and to flow, compress, and “gradient densify” (to be explained shortly) in a zone of the PET region immediately surrounding and adjacent the embedded object. Preferably, though not necessarily, relative-motion embedment is progressed to the point where what then becomes the outermost, exposed portion of the embedded object is substantially flush with the particular surface of the PET mass into which embedment has taken place.
Significantly, with such zonal gradient densification occurring—a declining densification progressing outwardly from the embedded object into the surrounding PET material—the collective post-embedment volume of (a) the embedding PET material, and (b) of the portion, or the whole, of the embedded object, is substantially equal to the starting, selected (predetermined) volume of just the initial PET material alone. This feature, which is referred to herein as a volume maintenance feature, uniquely allows for precise, overall product-configuration, dimensional-tolerance control in a pre-planned, final, composite-material product simply through the pre-selection of the shape and size of the receiving PET material, and through relying on local-embedment-region, or zone, PET-material gradient densification to maintain and control final product size, etc., by not swelling the overall size of the original, starting mass of PET material.
Subsequent cooling of the PET material following heating and embedding of a selected object, we have observed, causes in all cases a good mechanical bond to establish between the PET material and the received object. This bond functions very successfully to anchor the received object with the PET material. Bond security is, of course, enhanced where the outside configuration of an embedded object has appropriate “protrusions” that cause the object to become positively “captured” within the embedding material.
With heating and flowing of the PET material during the embedment process, as just generally outlined, because of the relative-motion embedment pressure which is employed, the mentioned PET-material gradient-densification which then occurs creates an important PET continuous density gradient in the “immediately adjacent” zone of embedding PET material (i.e., immediately adjacent the embedded object), which gradient functions as a strengthened region around a received object. This region, which has a density gradient characterized by greater PET density directly next to the embedded object, “tapering” to “normal” PET density a short distance away from the embedded object, is without any internal, sharp-discontinuity, stress-risers. This strengthened region both provides a “hardened”, protective jacket adjacent the associated embedded object, and also acts like an internal, structural reinforcing element within the PET material per se—an “element” which is very useful in certain applications. For example, a vehicle door panel prepared with embedded winds or reverse-bend loops of radio antenna wire in accordance with practice of the invention, effectively possesses an invisible, wire-shape-matching internal stiffening brace.
Thus, we have determined that, utilizing such PET material, along with certain, selected “embedment” materials and objects, it is possible to create a wide range of extremely versatile and useful structures, such as panel structures, or panels, in which embedded objects, put into place in accordance with practice of this invention, can provide a number of useful, different, “embedded-object” functions. For example, and repeating in certain instances illustrations which have already been given, panels which may be used on various structures, such as buildings, boats, airplanes and other vehicles, may carry (a) embedded wiring for heating or radio-reception/transmission purposes (as well as for other purposes), (b) embedded fluid conduits for carrying various kinds of fluids, such as heating and cooling fluids, (c) different kinds of embedded sensors, such as acoustic sensors, heat sensors, radioactivity sensors, and so on, (d) various fabrics, for selected purposes, and (e) many other kinds of embedded objects, like various reception-attaching, or fastening, devices such as screw-threaded nuts, hardware hinges, etc.
With regard, as an illustration, to the embedment typically (although not exclusively) of relatively-small fastening devices, a very unique procedure proposed herein involves the practice of heating a to-be-received (embedded) fastening device to an appropriate temperature (such as around 300° F.), and then, utilizing modest, relative-motion pressure, simply advancing this heated device into the PET material to cause localized PET melting and flowing to accommodate embedment. In this specific practice approach of the invention, heat from the heated “to-be-embedded” device operates at the contact interface which develops and exists between this device and the receiving (embedding) PET material to cause an appropriate, local PET state change from solid to effectively flowable liquid.
In one modified form of the invention, the surface of a PET mass into which embedment is to take place is first covered with a fibre-strand-reinforced thermoformable plastic layer material, such as the material sold under the trademark Polystrand®, manufactured by a company having the same name, Polystrand, in Montrose, Colo. The plastic in this layer material is preferably made of polypropylene, and the reinforcing strands are preferably made of E-glass. This layer material, which may actually be formed from plural (such as about twelve) sub-layers of the same material, might typically have an overall thickness of about 0.16-inches. The plastic in this layer solid-to-flowability state-change preferably has a melting temperature like that of PET.
These and other features and advantages which are offered by the present invention will become more apparent shortly as the detailed description of the invention presented below is read in conjunction with the accompanying drawings.
Turning attention now to the drawings, and referring first of all to
Two core components are involved specifically in what is shown in
Object 24 will be referred to herein as being a metallic object, though this is not in any way a constraint associated with practice of the invention.
In solid outline in
In a dashed line at 24A in
Two other components—optional components—are shown at 34, 36 in
In order to produce a composite-material product with object 24 embedded as shown in PET panel 22, heat is applied effectively in region 26 at a level which is sufficient to cause a state-change from solid to flowable-liquid in an appropriately sized and selected portion of the PET material intended to receive, by embedment, object 24. Under this condition, object 24 is relative-motion advanced (see arrow 27 in
Heating to a process temperature of about 300° F. the mentioned “embedment-receiving” portion of the PET panel material may be accomplished in any one of several different ways. One of these ways includes applying heat directly, and solely only, to the PET material, per se, in region 26. Another approach involves simply heating object 24 alone to an appropriate temperature whereby, when it is pressed into contact with the PET material, it will effect a solid-to-liquid state change in the PET material which will allow pressure embedment of the object. A third heating approach involves heating both panel 22 and object 24 in the region (26) embraced by arrows 28, 30.
With each of these heating approaches, object embedment is enabled wherein flowing PET material closes tightly upon the portion of that object which is pressed into the PET material. PET gradient densification occurs during embedding of the object, and this densification causes the unique “volume maintenance” feature of the invention described earlier. This volume maintenance feature ensures dimensional tolerance maintenance of the initial outside dimension(s) and configuration of the starter body of PET material.
Following complete and proper embedment of object 24, and as a consequence thereof, there exists within the PET material a density gradient zone 22A which transitions continuously (i.e., without any discontinuity), and with spatial declination, from relatively dense in the locations immediately adjacent the embedded object, to the lesser, normal density of the PET material, per se. More will be said later about this density gradient zone, also referred to herein as a “declining, transitioning gradient” zone, which becomes created during object embedment.
Following proper embedment of object 24, the composite, “embedded assembly” of components 22, 24 is allowed to cool in a manner causing the selected region of PET material which became flowable to go through a state change from liquid to solid. When this change has occurred, object 24 is securely embedded and anchored in the PET material, and the desired, end-result, composite-material product is fully created.
In certain instances, for example, for added-strength purposes, it may be desired to clad one or both of faces 22 a, 22 b with a material such as that described for layer components 34, 36. These layer components, or one of them, may readily be applied to a selected face in the embedment-process structure through appropriate heat application and associated pressure to achieve thermal-clad-bonding of the composite product and the selected cladding layer.
Again, an additional surface-cladding layer, or layers, such as layers 34, 36, may be applied to one or both of panel face(s) 22 a, 22 b in
As was just mentioned above, in
With elongate element 24 in
This zone (22A) which possesses the mentioned density gradient furnishes reinforced support around embedded object 24, and additionally acts somewhat like an internal reinforcing structure, or brace, within the PET panel material, per se.
In one invention embodiment which is pictured in both
The presence of fasteners 40, 42 of square heads which are embedded in PET panel 44 positively assures that use of these fasteners will not cause them to rotate free of being bound in the PET material.
As those skilled in the art will appreciate, various forms of fasteners may be utilized in the practice of the invention, including fasteners which are accessible from one surface only of the associated PET material, or possibly accessible from opposite sides of such material.
Turning attention now to
From one point of view, as seen in
While just a few panel-like resulting devices have been mentioned and are illustrated herein, and while certain formation procedures have been described, it will apparent to those skilled in the art that many other useful PET-embedded devices, and techniques for producing embedment thermally, may be thought of by those generally skilled in the relevant art. It will be apparent, for example, that, with respect to the making of various unique panel structures, it is possible to create what may be thought of as being “smart panels” which include PET-embedded hardware capable of functioning in various ways.